28 MICRO-ORGANISMS AND DISEASE. [CHAP. 



large vein is required, separate the vessel with clean instru- 

 ments, and make a small incision with clean scissors and push 

 the pointed end of the capillary pipette well forward. If 

 juice of a lymphatic gland, or spleen, or other parenchymatous 

 organ be required, pierce the organ after having washed its 

 surface with solution of perchloride of mercury (Koch), with 

 the pointed end of a capillary pipette, then push it into the 

 part required for a little distance, and squeezing the organ 

 press a drop or two of the juice into it. The same procedure 

 is adopted when the pus of an abscess is required, the wall of 

 which can be pierced with the pointed end of the capillary 

 pipette. If not, a slight incision is made and the pipette 

 introduced through this into the abscess. If blood of a living 

 animal is required, expose a vessel with clean instruments, make 

 a small incision with clean scissors, push through this incision 

 the pointed end of the capillary pipette well forward, and allow 

 the blood to rise into the capillary tube. If blood of a living 

 human being is required, clean well with soap and water and 

 then with strong carbolic acid or perchloride of mercury solution 

 the tip of a finger, make a venous congestion in the last phalanx 

 by compressing it with a corner of a hankerchief, prick the 

 volar skin of the phalanx with a clean (overheated and cooled) 

 needle, and plunging the pointed end of the pipette into the 

 drop of blood allow a droplet to ascend into the capillary tube 

 of the pipette. 



If solid tissues or parts of tissues are required, e.g. the base 

 of an ulcer, a tubercle of the liver, spleen, or lung, it is possible 

 to squeeze into the capillary tube of a pipette, after pushing its 

 pointed end into the part, a small droplet of juice of the part 

 required ; but if this be not practicable, i.e. if a solid particle 

 be required, then follow Koch's method. This is as follows : 

 cut with clean scissors or scalpel into the part, dig out rapidly 

 with the point of a needle or platinum wire previously over- 

 heated in the flame of a burner a small particle, and quickly 

 introduce this into the culture-tube to the place required, e.g. 

 surface or depth of a solid or fluid nourishing material. Of 

 course in this case the cotton- wool must be altogether lifted, 

 and therefore contamination with organisms is possible. But 

 inoculating several tubes at once and performing the operation 

 quickly, one always succeeds in getting some of tjie tubes 

 without any air- contamination. I have inade numerous in- 

 oculations with solid particles (tubercles) in this manner, and 

 like Koch have seen only a small percentage of tubes going 

 Lad through contamination with air- organisms. 



The same plan, i.e. of using the clean point of a needle or 



